meshio++I/O for many mesh formats

One unified mesh data model, 35+ file formats, a fast C++ core with pure-Python fallbacks.

35+ formats

Read and write VTK, VTU, XDMF, Gmsh, MED, Exodus, CGNS, Abaqus, Nastran, UNV, COMSOL, FLUX, and many more — all through a single API.

Unified data model

A single Mesh object (points, cells, point/cell data, field data, sets) bridges every format, so conversion is one call.

Fast C++ core

A pybind11 extension with zero-copy numpy at the I/O boundary and optional HDF5/netCDF acceleration — with pure-Python fallbacks everywhere.

Swappable mesh backends

Standalone C++ builds choose the in-memory structure at compile time — the meshio-mirroring default, a fastest-possible native layout (used by the WASM build), or a Kratos Multiphysics-style ModelPart with a header-only bridge.

What is meshio++?

meshio++ reads and writes unstructured mesh files. It supports over 35 formats and provides one unified data model so you can convert between any of them, from the command line or from Python:

python

import meshioplusplus

mesh = meshioplusplus.read("input.msh")   # format inferred from the extension
mesh.write("output.vtu")

meshioplusplus convert input.msh output.vtu
meshioplusplus info input.xdmf

See the Quickstart to get going, the Supported formats table for the full list and per-format options, and the CLI reference for the command-line tools.